scholarly journals Dynamic modeling and analysis of vertical vibration reduction system for passenger train

Mechanika ◽  
2021 ◽  
Vol 27 (5) ◽  
pp. 415-420
Author(s):  
Shichang Dong ◽  
Hao Song ◽  
Caiyun Song
Keyword(s):  
Dynamical Behavior ◽  
Vibration Reduction ◽  
Vertical Vibration ◽  
The Body ◽  
Degree Of Freedom ◽  
Modeling And Analysis ◽  
Impact System ◽  
Reduction System ◽  
Train Operation ◽  
The Stability

Based on wheel-rail impact vibration and considering the body stiffness and natural damping, this paper builds a four-degree-of-freedom vibro-impact system model for passenger train’s vertical vibration reduction system. The Poincaré map of the system is determined by the analytic solution of the system derived from the motion differential equation of the multi-degree-of-freedom vibro-impact system combined with Newton's second law. It is found that the fork bifurcation, Hopf bifurcation and other dynamical behavior leading to Chaos when the system parameters are changed. On this basis, the dynamic parameters of the train are optimized to avoid chaos in the train operation, reduce the vertical vibration of the train, improve the stability and comfort of the train operation, and provide the theoretical basis for the active vibration reduction design of the train.

EXPERIMENTAL INVESTIGATION OF A TWO-DEGREE-OF-FREEDOM VIBRO-IMPACT SYSTEM

2012 ◽  
Vol 22 (05) ◽  
pp. 1250110 ◽  
Author(s):  
GUILIN WEN ◽  
HUIDONG XU ◽  
LU XIAO ◽  
XIAOPING XIE ◽  
ZHONG CHEN ◽  
...  
Keyword(s):  
Dynamical Behavior ◽  
Degree Of Freedom ◽  
Modeling And Analysis ◽  
Strongly Nonlinear ◽  
Impact System ◽  
Dynamical Behaviors ◽  
Nonsmooth Systems ◽  
Experimental Apparatus ◽  
Thick Steel ◽  
Two Degree Of Freedom

Vibro-impact systems with intermittent contacts are strongly nonlinear. The discontinuity of impact can give rise to rich nonlinear dynamic behaviors and bring forth challenges in the modeling and analysis of this type of nonsmooth systems. The dynamical behavior of a two-degree-of-freedom vibro-impact system is investigated experimentally in this paper. The experimental apparatus is composed of two spring-linked oscillators moving on a lead rail. One of the two oscillators connected to an excitation system intermittently impacts with a spherical obstacle fixed on the thick steel wall. With different gap sizes between the impacting oscillator and the obstacle, the dynamical behaviors are investigated by changing the excitation frequencies. The experimental results show periodic, grazing and chaotic dynamical behaviors of the vibro-impact system.

scholarly journals Mathematical Modeling and Analysis of an Alcohol Drinking Model with the Influence of Alcohol Treatment Centers

2020 ◽  
Vol 2020 ◽  
pp. 1-12 ◽  
Author(s):  
Bouchaib Khajji ◽  
Abderrahim Labzai ◽  
Omar Balatif ◽  
Mostafa Rachik
Keyword(s):  
Alcohol Drinking ◽  
Addiction Treatment ◽  
Reproduction Number ◽  
Dynamical Behavior ◽  
Model Parameters ◽  
Asymptotically Stable ◽  
Globally Asymptotically Stable ◽  
Modeling And Analysis ◽  
Private And Public ◽  
The Stability

In this paper, we present a continuous mathematical model PMHTrTpQ of alcohol drinking with the influence of private and public addiction treatment centers. We study the dynamical behavior of this model and we discuss the basic properties of the system and determine its basic reproduction number R0. We also study the sensitivity analysis of model parameters to know the parameters that have a high impact on the reproduction number R0. The stability analysis of the model shows that the system is locally as well as globally asymptotically stable at drinking-free equilibrium E0 when R0≤1. When R0>1, drinking present equilibrium E∗ exists and the system is locally as well as globally asymptotically stable at alcohol present equilibrium E∗.

Elastically Mounted Body in Cross Flow With an Attached Pendulum

1993 ◽  
Author(s):  
Aleš Tondl
Keyword(s):  
Vortex Shedding ◽  
Parametric Excitation ◽  
Trivial Solution ◽  
Cross Flow ◽  
Vertical Vibration ◽  
The Body ◽  
Autoparametric Resonance ◽  
Vortex Shedding Frequency ◽  
Shedding Frequency ◽  
The Stability

Abstract A pendulum is attached to an elastically mounted body in cross flow. The body is excited due to the action of vortex shedding. The stability of the semi-trivial solution (representing the vibration of the body with the non-oscillating pendulum) is investigated. It is proved that a certain interval of the vortex shedding frequency can exist where the semi-trivial solution representing the vertical vibration of the body is unstable. The body vibration is the source of parametric excitation of the pendulum resulting in autoparametric resonance.

The Stability and Chaos Analysis of a Nonlinear Wheeled Vehicle Model Under Road Excitation

2010 ◽  
Author(s):  
Hamed Samandari ◽  
Mousa Rezaee
Keyword(s):  
Dynamical Behavior ◽  
Great Influence ◽  
Surface Profile ◽  
Degree Of Freedom ◽  
The Road ◽  
Roughness Amplitude ◽  
Road Excitation ◽  
Quarter Car ◽  
The Stability ◽  
Unsprung Mass

In this paper, the dynamic behavior of a quarter-car with two degree-of-freedom which consists of sprung mass and unsprung mass is examined. Nonlinearity occurred due to nonlinear hysteretic suspension damper and spring. Vehicle tire is modeled as a nonlinear hardening spring. The disturbance of road assumed to be sinusoid. Frequency response diagram of the model has been obtained. Results show that the dynamic response of the vehicle can be chaotic. Influence of road roughness amplitude on vehicle vibration is investigated and critical amplitude of the road surface profile is found, above which the system can vibrate chaotically. The comparison between the results obtained from the proposed model and those from the single degree-of-freedom quarter-car model shows that the unsprung mass has great influence on the dynamical behavior of the system, which cannot be ignored.

THE CHARACTERISTICS OF ARTIFICIAL RICE WITH SEAWEED Eucheuma cottonii ADDITION AS A DIETARY FIBER SOURCE

2014 ◽  
Vol 6 (1) ◽  
Author(s):  
Natalia Prodiana Setiawati ◽  
Joko Santoso ◽  
Sri Purwaningsih
Keyword(s):  
Blood Glucose ◽  
Dietary Fiber ◽  
Dietary Fibre ◽  
Extrusion Process ◽  
The Body ◽  
Starch Digestibility ◽  
Food Commodities ◽  
The Stability ◽  
Extrusion Technology ◽  
Eucheuma Cottonii

The utilization of local food commodities such as corn and cassava with seaweed addition as a dietary fiber source for producing artificial rice through extrusion technology is an  alternative for food diversification. The research was carried out to find out the best composition (rice, corn, cassava, and seaweed) and temperature of extrusion process on making artificial rice and the influence of dietary fibre on sensory properties and physicochemical. The composition of rice, corn, and cassava in proportion  of 1:3:1 with 20% seaweed, Eucheuma cottonii, addition and temperature extruder of 90 °C were selected as the best product for artificial rice. The  sensory evaluation was 8.02±0.21 (people’s preference). In physicochemical properties, dietary fiber significantly affected on low bulk density and starch digestibility. This condition is very good for health especially in maintaining the stability of blood glucose in the body. Keywords: artificial rice, composition, extrusion, seaweed, dietary fibre, temperature

Substantiation the machine with a basket for the application of mineral fertilizers and other bulk materials with the upper arrangement of the feeding device

2019 ◽  
pp. 37-43
Author(s):  
Fesenko, H.
Keyword(s):  
Fat Body ◽  
Mineral Fertilizer ◽  
The Body ◽  
Mineral Fertilizers ◽  
Analytical Mechanics ◽  
Bulk Materials ◽  
The Stability ◽  
Working Bodies ◽  
The Relationship ◽  
Stable Flow

Purpose. Increasing the uniformity of distribution of mineral fertilizers and other bulk materials due to the stability of their feed from the body to the spreading working bodies using the top feeder. Methods. The following methods are used to achieve this aim: the method of comparing the differences between individual groups of fertilizers, the method of analyzing the properties of a new technical system, the method of functional inventiveness, and the methods of theoretical and analytical mechanics. Results. The traction body of the conveyor of the upper feed of the body fat body machine for mineral fertilizers and other bulk materials was substantiated and the relationship between the height of its scrapers and the distance between them was established, as well as the nature of the mineral fertilizer pressure on the curvilinear wall of the body. In addition, the design of the advanced body fertilizer spreader is justified, which ensures a stable flow of fertilizers from the body due to the improvement of the top feeder. Conclusions. Because of the conducted researches, the advantages of machines equipped with top feeder are found. They create the conditions for the forced feeding mineral fertilizers and other loose materials from the container to the distribution bodies, which is a prerequisite for their evenness on the surface. With this, the imperfection of known machines with the top feeder constrains their introduction into agricultural production. On this account, a more thoroughly constructed solution of the body feeder of the top feed is substantiated, in which the conveyor provides a stable supply of fertilizers from the body with reduced energy consumption during operation. Keywords: analysis, feed, upper device, conveyor, stability, fertilizers, flow ability, body.

Novel Nanolipoidal Systems for the Management of Skin Cancer

2020 ◽  
Vol 14 (2) ◽  
pp. 108-125
Author(s):  
Apoorva Singh ◽  
Nimisha
Keyword(s):  
Skin Cancer ◽  
Survival Rates ◽  
Cancer Therapeutics ◽  
The Body ◽  
Surgical Removal ◽  
The Novel ◽  
Skin Cancers ◽  
Recent Developments ◽  
Abnormal Cells ◽  
The Stability

: Skin cancer, among the various kinds of cancers, is a type that emerges from skin due to the growth of abnormal cells. These cells are capable of spreading and invading the other parts of the body. The occurrence of non-melanoma and melanoma, which are the major types of skin cancers, has increased over the past decades. Exposure to ultraviolet radiations (UV) is the main associative cause of skin cancer. UV exposure can inactivate tumor suppressor genes while activating various oncogenes. The conventional techniques like surgical removal, chemotherapy and radiation therapy lack the potential for targeting cancer cells and harm the normal cells. However, the novel therapeutics show promising improvements in the effectiveness of treatment, survival rates and better quality of life for patients. Different methodologies are involved in the skin cancer therapeutics for delivering the active ingredients to the target sites. Nano carriers are very efficient as they have the ability to improve the stability of drugs and further enhance their penetration into the tumor cells. The recent developments and research in nanotechnology have entitled several targeting and therapeutic agents to be incorporated into nanoparticles for an enhancive treatment of skin cancer. To protect the research works in the field of nanolipoidal systems various patents have been introduced. Some of the patents acknowledge responsive liposomes for specific targeting, nanocarriers for the delivery or co-delivery of chemotherapeutics, nucleic acids as well as photosensitizers. Further recent patents on the novel delivery systems have also been included here.

scholarly journals Modeling and Analysis of BDS-2 and BDS-3 Combined Precise Time and Frequency Transfer Considering Stochastic Models of Inter-System Bias

2021 ◽  
Vol 13 (4) ◽  
pp. 793
Author(s):  
Guoqiang Jiao ◽  
Shuli Song ◽  
Qinming Chen ◽  
Chao Huang ◽  
Ke Su ◽  
...  
Keyword(s):  
Stochastic Models ◽  
Satellite System ◽  
Modeling And Analysis ◽  
System Bias ◽  
Frequency Transfer ◽  
Global Navigation ◽  
The Difference ◽  
The Stability ◽  
Global Navigation Satellite ◽  
Precise Time

BeiDou global navigation satellite system (BDS) began to provide positioning, navigation, and timing (PNT) services to global users officially on 31 July, 2020. BDS constellations consist of regional (BDS-2) and global navigation satellites (BDS-3). Due to the difference of modulations and characteristics for the BDS-2 and BDS-3 default civil service signals (B1I/B3I) and the increase of new signals (B1C/B2a) for BDS-3, a systemically bias exists in the receiver-end when receiving and processing BDS-2 and BDS-3 signals, which leads to the inter-system bias (ISB) between BDS-2 and BDS-3 on the receiver side. To fully utilize BDS, the BDS-2 and BDS-3 combined precise time and frequency transfer are investigated considering the effect of the ISB. Four kinds of ISB stochastic models are presented, which are ignoring ISB (ISBNO), estimating ISB as random constant (ISBCV), random walk process (ISBRW), and white noise process (ISBWN). The results demonstrate that the datum of receiver clock offsets can be unified and the ISB deduced datum confusion can be avoided by estimating the ISB. The ISBCV and ISBRW models are superior to ISBWN. For the BDS-2 and BDS-3 combined precise time and frequency transfer using ISBNO, ISBCV, ISBRW, and ISBWN, the stability of clock differences of old signals can be enhanced by 20.18%, 23.89%, 23.96%, and 11.46% over BDS-2-only, respectively. For new signals, the enhancements are −50.77%, 20.22%, 17.53%, and −3.69%, respectively. Moreover, ISBCV and ISBRW models have the better frequency transfer stability. Consequently, we recommended the optimal ISBCV or suboptimal ISBRW model for BDS-2 and BDS-3 combined precise time and frequency transfer when processing the old as well as the new signals.

scholarly journals Polymer-Drug Conjugates as Nanotheranostic Agents

2021 ◽  
Vol 2 (1) ◽  
pp. 63-81
Author(s):  
Sajana Manandhar ◽  
Erica Sjöholm ◽  
Johan Bobacka ◽  
Jessica M. Rosenholm ◽  
Kuldeep K. Bansal
Keyword(s):  
Drug Delivery ◽  
Drug Release ◽  
Treatment Options ◽  
The Body ◽  
Drug Conjugates ◽  
Imaging Characteristics ◽  
Wide Range ◽  
Systemic Side Effects ◽  
Theranostic Agents ◽  
The Stability

Since the last decade, the polymer-drug conjugate (PDC) approach has emerged as one of the most promising drug-delivery technologies owing to several benefits like circumventing premature drug release, offering controlled and targeted drug delivery, improving the stability, safety, and kinetics of conjugated drugs, and so forth. In recent years, PDC technology has advanced with the objective to further enhance the treatment outcomes by integrating nanotechnology and multifunctional characteristics into these systems. One such development is the ability of PDCs to act as theranostic agents, permitting simultaneous diagnosis and treatment options. Theranostic nanocarriers offer the opportunity to track the distribution of PDCs within the body and help to localize the diseased site. This characteristic is of particular interest, especially among those therapeutic approaches where external stimuli are supposed to be applied for abrupt drug release at the target site for localized delivery to avoid systemic side effects (e.g., Visudyne®). Thus, with the help of this review article, we are presenting the most recent updates in the domain of PDCs as nanotheranostic agents. Different methodologies utilized to design PDCs along with imaging characteristics and their applicability in a wide range of diseases, have been summarized in this article.

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